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Counties Manukau Health Laboratory Services

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Biochemistry Tests

This group of tests includes: liver, kidney and thyroid function tests; diabetes tests and lipid (fats), electrolyte (potassium, sodium, chloride), hormone and drug level tests.
 
Liver Function Tests
Liver function can be measured by looking at blood levels of the liver enzymes AST, ALT, ALP and GGT or levels of other substances produced by the liver.
High levels of liver enzymes may indicate, among other things: viral hepatitis or other viral infections, the presence of a tumour, alcoholism or diabetes.
You may have to fast (not eat or drink) before some of these tests; check with your doctor or the laboratory first.
 
Renal (Kidney) Function Tests
Several blood tests will give an indication of how well your kidneys are functioning. These include the serum creatinine test and the urea test. Other renal tests include measurement of potassium and sodium levels and uric acid levels in the blood. High uric acid levels can be a cause of gout (an inflammatory arthritic disease with painful, swollen joints).
You may eat and drink normally before having these tests.
 
Thyroid Function Tests
The thyroid is a gland at the base of your neck that secretes thyroid hormone (T4), a hormone that affects your body’s metabolism.
Common blood tests that measure how well your thyroid gland is working are TSH (thyroid-stimulating hormone) and T4 level tests.
You may eat and drink normally before having these tests.
 
Enzyme Tests
Creatine Kinase (CK) is an enzyme that can be measured in the blood. Increased levels can be caused by: a lot of exercise, muscle damage and viral infections, but more importantly can indicate that a myocardial infarction (MI or heart attack) has occurred.
Troponins are cardiac (heart) enzymes which are higher following a heart attack.
You may eat and drink normally before having these tests.
 
 Diabetes Tests
Diabetes is a disease that affects the way your body deals with sugar. The amount of sugar in your blood is controlled by insulin, a hormone produced by the pancreas (an organ that lies near your stomach).
The levels of sugar (glucose) in your blood can be measured either when you have fasted (not eaten) for 12 hours (fasting blood glucose) or after drinking and eating normally (casual or random blood glucose). Blood glucose testing can be used to diagnose diabetes or can be used to measure how well your diabetes is being controlled.
The HBA1C (glycated haemoglobin) test measures how well your diabetes has been controlled for the last three months. If you have diabetes, you will probably have this test done once or twice every year.
The glucose tolerance test helps a doctor diagnose diabetes if your blood glucose levels are normal but you have some of the symptoms of diabetes. This test is also used to diagnose diabetes during pregnancy (gestational diabetes). The test measures blood glucose levels before and after having a glucose drink.
You may have to fast (not eat or drink) before some of these tests; check with your doctor or the laboratory first.
 
Lipid Tests
The lipids (fats) measured in blood are cholesterol and triglycerides. Cholesterol can be high-density (HDL cholesterol) or low-density (LDL cholesterol). LDL cholesterol is associated with heart disease, but HDL cholesterol is the opposite and can protect against heart disease. Measuring fat levels in your blood can show if you are at risk of developing heart disease.
You may have to fast (not eat or drink) before some of these tests; check with your doctor or the laboratory first.
 
Medicine Level Tests
It is possible to measure the levels of some medicines in the blood. Sometimes it is important to do this to make sure that you are not taking too much of a particular medicine. Medicines that may be monitored this way include: digoxin, lithium, theophylline and some anticonvulsants. Alcohol levels in the blood can also be measured.
 
Hormone Tests
Measuring levels of the gonadotrophin hormones FSH (follicle-stimulating hormone) and LH (luteinising hormone) in your blood can help diagnose infertility (inability to have children), menstruation (period) problems, early-onset puberty (precocious puberty), premature menopause, or testicular failure.
Progesterone is another hormone that may be measured in your blood to see if your ovaries are working properly and can also be used to see if the placenta is working properly during pregnancy.
You may eat and drink normally before having these tests.
 
Tumour Marker Tests
Measuring blood levels of certain chemicals can indicate the progression of particular diseases.
The AFP (alpha-foetoprotein) test can monitor the progress of liver or testicular cancer.
The PSA (prostate-specific antigen) test is used in patients with prostate cancer.

This page was last updated at 11:35AM on August 25, 2016.